If you use voice apps like Skype or Viber on an Airtel data plan to make calls, you’re in for a rude surprise. Bharti Airtel has changed the terms and conditions on its mobile packs to charge standard data rates on VoIP based services. As pointed out by Telecomtalk, the new T&C adds this footnote:

In other words, you would have to pay up to Rs10,000 per GB of data consumption on 2G networks and Rs4,000 per GB on 3G networks for making calls on Skype or Viber, even if you have a 2G or 3G data pack active on your phone.

Here's what Wolfram Alpha says about how much time on Skype will eat up that kind of data. For a high quality video call, Skype requires 500kbps and 500kbps downstream speeds. You would run out of 1 GB in 2.2 hours. For an audio call it recommends 100kbps speeds. At that rate, it could consume 90 MB of data for 1 hour of voice calls.

In a statement, an Airtel representative confirmed the change in terms and conditions, saying it is a precursor to launching dedicated VoIP packs. "We have made some revisions in the composition of our data packs, and will offer VoIP (Voice over internet protocol) connectivity through an independent pack that will be launched shortly. Our customers can continue enjoying voice calls over data connectivity by opting for this VoIP pack, or simply use VoIP services on pay-as-you-go basis.”

In doing this, Airtel violates the idea of principle of net neutrality, regarded as an essential ground rule for an open internet. Fundamentally it means carriers should treat all data equally and should not be allowed to impose differential treatment or charges on different kinds of data.

India does not have a law regarding net neutrality, the Telecom Regulatory Authority of India recommends that "the Licensee can provide video conferencing and audiotex services in a non-discriminatory basis.”

Fundamentally, the problem is this—telcos in India pay high fee for a telecom license to provide voice services over traditional mobile networks. Customers with internet access increasingly prefer to make calls and send texts using apps such as Skype, Viber and Whatsapp, all of which are free of cost. Whatsapp has already killed SMS revenues and telcos in India fear that as internet speeds grow, such apps, based on a technology called Voice over Internet Protocol (VoIP), will eat into voice revenues. Sooner or later, every telco will start worrying about this.

India's telecom policy, which predates the popularity of VoIP apps, will take time to keep up.

"I do believe that the Airtel decision to separate VoIP from other data services is a worrying trend. While this is a very dangerous road to take, some regulatory anomalies seem to provide an excuse for this," said telecom analyst Mahesh Uppal, who runs the consulting firm Com First. He points out that the Indian Telegraph Act requires a telecom service provider to have a license. "There are fees too. Mobile players like Airtel pay high license fees in the form of share of revenue and for the use of spectrum. Taken together, the companies' payments run into billions of dollars." he added.

"Several OTT (over the top) services, like Skype, Viber and WhatsApp are similar in functionality to conventional telephony or messaging services. WhatsApp is arguably even more powerful than SMS. The rules that govern functionally similar services must be comparable too. What we need to do is ensure that the regulatory burden is the same. The way is not to increase it for OTT services but to remove the high levies on current providers of conventional services," Uppal said.

With net neutrality at stake, VoIP users on Twitter voiced their displeasure at Airtel, threatening to boycott their service.